Hot water boiler

ABSTRACT

A hot water boiler comprising an elongated cylindrical combustion chamber surrounded by an annular water jacket, said boiler comprising means for directing the flue gases forwardly through said combustion chamber and then rearwardly along the outside of said water jacket whereby maximum heat transfer between said flue gases and water jacket is effected.

United States Patent 1 1 Salvo 1 Sept. 9, 1975 HOT WATER BOILER [76]Inventor: Anthony Salvo, 1219 Main Rd,

Tiverton, R1. 02873 221 Filed: Aug. 5, 1974 211 App]. No.1 495,128

[52] US. Cl. 126/361; 126/362; 122/37; 122/136 R [51] Int. Cl. H F24111/00 [58] Field of Search 122/136 11.37; 126/361 126/362, 350 R [56]References Cited UNITED STATES PATENTS 8/1908 Mackley .1 122/161 1/1934Brandt H 5/1936 Schumann 122/136 R 2.531 459 11/1950 Marshall Jr.122/136 R FOREIGN PATENTS OR APPLICATIONS 1,526,932 1/1966 Germany122/136 R Primary Emminer-Carroll B. Dority, 11'. AssistantExaminer-Larry l. Schwartz Attorney, Agent, or Firm-Salter & Michaelson1 5 7 1 ABSTRACT A hot water boiler comprising an elongated cylindricalcombustion chamber surrounded by an annular water jacket, said boilercomprising means for directing the flue gasses forwardly through saidcombustion chamber and then rearwardly along the outside of said waterjacket whereby maximum heat transfer between said flue gases and waterjacket is effected.

6 Claims, 4 Drawing Figures ABM-3,868

mu, M

sum 2 of 3 HOT WATER BOILER BACKGROUND AND SUMMARY OF THE INVENTION Thepresent invention relates generally to a hot water boiler of the typeused in home or small industrial heating systems wherein water from thesystem is continuously circulated through the boiler and is heatedthereby.

The basic and prevalent problem in connection with hot water boilers ofthis type is to obtain maximum output efficiency, i.e., maximum heatingof the circulating water at a given combustion rate. Obviously, greaterboiler efficiency results in a greater heating capacity for a given sizeboiler and at the same time minimizes fuel consumption, which in view ofpresent energy shortages, is a highly important feature. While theconventional hot water boiler will normally have an output efficiency inthe general range of 50 to 60%, it has been found that a hot waterboiler constructed in accordance with the present invention normally hasan output efficiency in the range of 90 to 92%.

It is therefore a primary objective of my invention to provide a hotwater boiler that is highly effective for home and small industrial use;since, due to its relatively high efficiency, a relatively greatercapacity of heating is obtained for a given fuel consumption rate. Inaddition, due to its relatively high efficiency, the boiler of thepresent invention may be of relatively small size, which is an obviousadvantage from an installation standpoint.

Generally speaking, the above stated objectives are achieved byproviding a boiler having an inner combustion chamber surrounded by anannular water jacket, the boiler being so constructed that the fluegases pass rearwardly through said combustion chamber and then areforced forwardly along the outside surface of the annular water jacketto a point of exhaust. Thus, the circulating water within the waterjacket receives maximum heat transfer from the flue gases, since thepath of the latter is such that not only is the inner surface of theannular water jacket contacted by said flue gases, but also the outersurface of the water jacket is in Contact with the flue gases during thereturn thereof.

Where greater heating capacity is required, it has been found feasibleto exhaust the flue gases to a second water jacketed chamber throughwhich the flue gases pass, and then return along the outside surface ofthe water jacket in the same manner as previously described.

Other objects, features and advantages of the invention will becomeapparent as the description thereof proceeds when considered inconnection with the accompanying illustrative drawings.

DESCRIPTION OF THE DRAWINGS In the drawings which illustrate the bestmode presently contemplated for carrying out the present invention:

FIG. 1 is an elevational view, in section, of a hot water boilercomprising the present invention;

FIG. 2 is an elevational view, in section, of a modified form of boilerembodying the present invention;

FIG. 3 is a section taken on line 33 of FIG. 1; and

FIG. 4 is a section taken on line 4-4 of FIG. 2.

DESCRIPTION OF THE INVENTION Referring to the drawings, and moreparticularly to FIGS. 1 and 3 thereof, there is shown generally at 10 ahot water boiler comprising a cylindrical housing defined by cylindricalouter wall 12, front cover 14, and rear cover 16. As will be seen mostclearly in FIG. I, outer cylindrical wall 12 actually comprises a steelshell filled with suitable insulation material 18, while the covers 14and 16, also constructed of a structurally strong material, such assteel, are lined with heat insulating material, as shown at 20, 22 and24. The cover members 14 and 16 are removably secured to cylindricalwall 12 by any suitable means, such as bolts 26.

Concentrically and axially positioned within outer wall 12, andextending from the inner surface of front cover 14, is a combustionchamber 28, said combustion chamber being surrounded by an annular waterjacket 30. More specifically, water jacket 30 is defined by an innersteel cylindrical wall 32, which wall defines com bustion chamber 28, anouter steel cylindrical wall 34, and end walls 36, 38. It is importantto note that water jacket 30 and hence combustion chamber 28 terminateshort of rear cover 16. Expressed differently, end walls 36 of waterjacket 30 are in spaced relation to the inner surface of insulatinglayer 24.

An inlet conduit 40 extends through front cover 14 into communicationwith water jacket 30 at a point closely adjacent to front cover 14.Conversely, outlet conduit 42 extends through front cover 14 andcommunicates with water jacket 30 at the location 44, which it will benoted is closely adjacent to rear cover 16. It will be understood thatcirculating water from the heating system continuously passes throughconduit 40 into annular water jacket 30 and then exits through conduit42 to again be circulated through the system.

Secured to rear cover 16, as by angle brackets 46, is an annularrestrictor plate 48, constructed of a structurally strong material, suchas steel, it being noted that said plate is located between and extendssubstantially parallel to annular wall 34 of water jacket 30 and theinner shell of outer cylindrical wall 12. It will further be noted thatrestrictor plate 48 terminates short of front cover 14. Adjacent tofront cover 14, and extending through outer wall 12, is exhaust stack50. It will be seen that the annular space located between restrictorplate 48 and the inner surface of outer Wall 12 is an unencumbered,substantially dead-air space which acts to further insulate the heatedflue gases flowing along the inner side of plate 48.

Secured to the outer surface of front cover 14, by any suitable means,such as bolts 52, is a conventional burner 54 which may be fueled by oiland which comprises firing nozzle 56 extending through opening 58 infront cover 14.

In operation and use, and with burner 54 firing at any desired capacity,which normally will be in the range of 1.75 to 2.75 gallons per hour,the heated flue gases pass rearwardly through combustion chamber 28following the direction of the arrows shown in FIG. 1. Upon reaching theend of chamber 28, the flue gases are forced outwardly and reverse theirdirection and pass forwardly between outside wall 34 of water jacket 30and annular restrictor plate 48, it being understood that plate 48physically forces and directs the flue gases against outside wall 34during the reverse flight of said gases. Upon reaching the end ofrestrictor plate 48, the

flue gases are free to exit outwardly through stack 50, it beingunderstood that a conventional draft associated with said stack willnormally suck said flue gases outwardly therethrough. In the meanwhile,water from the system is continuously being fed into water jacket 30 bymeans of conduit 40 and then is recirculated back into the system bymeans of conduit 42. Maximum heat transfer between the flue gases andwater jacket 30 is accomplished, because the flue gases not only engageinner wall 32 of the water jacket, but also engage outer wall 34 of thewater jacket during the return flight of the flue gases, as hereinbeforedescribed. It has been found that greater efficiency is obtained byexiting the heated water from water jacket 30 at location 44, since thisinsures that water exiting through conduit 42 will have been subjectedto substantial heat transfer before departure from the boiler.

It has been found that the hot water boiler 10, as illustrated anddescribed. will operate at an output efficiency of somewhere in therange of 90 to 92%. The boiler may be of relatively small size, and inactual practice a boiler having an overall length of approximately 5feet 4 inches and an outer diameter of approximately 2 feet 3 inches hasbeen found sufficient to effectively heat the average home. Where,however, greater capacity is required, it has been found possible tocombine the boiler with a second, somewhat similarly constructedhousing, shown generally at 60 in FIG. 2. The only difference betweenthe housing 60 shown in FIG. 2 and the boiler 10 shown in FIG. 1 is thefact that the exhaust stack 50 has benn eliminated, and in place thereofa stack or chimney 62 carries the heated flue gases from boiler 10 tochamber 64, the construction of which, it will be understood, isbasically the same as that of firing chamber 28. As will be clearly seenin FIG. 2, housing 60 comprises outer cylindrical wall 66 and front andrear covers 68, 70, all corresponding to like components in the boiler10. Likewise, chamber 64 is surrounded by water jacket 72 defined byinner and outer wall 74, 76, and a restrictor plate 78 extends forwardlyfrom rear cover 70, terminating short of chimney 62. In the form of myinvention illustrated in FIG. 2, the outlet conduit 42 shown in FIG. 1is eliminated, and in place thereof there is provided a transfer conduit80 which circulates water from water jacket 30 and boiler 10 to waterjacket 72 of housing 60. An outlet conduit 82 extends through frontcover 68 and communicates with water jacket 72 adjacent the forward endof the latter. An exhaust stack 84 extends through outer wall 66 tocarry off the flue gases.

In operation and use, burner 54 fires into chamber 28, and the heatedflue gases follow the exact same path as described in connection withthe form of my in vention illustrated in FIG. 1. However, after the fluegases have passed rearwardly along the outside surface 34 of waterjacket 30, the flue gases pass upwardly through chimney 62 and then passforwardly through chamber 64 and then rearwardly along the outsidesurface 76 of water jacket 72 and then are exhausted through stack 84.Meanwhile, circulating water from the heating system has entered waterjacket 30 via conduit 40 and passes through said water jacket totransfer conduit 80, which then introduces the water into water jacket72 of housing 60, from which the heated water exits via conduit 82 toonce again pass through the heating system. It will thus be seen thatthe benefits derived from the form of my invention illustrated in FIG.

l are perhaps derived to an even greater extent in the form of myinvention illustrated in FIG. 2, since the heated flue gases pass inseries along the inside and outside of two separate water jackets, thusresulting in greater total heat transfer than in the embodiment of FIG.1 where only one housing and water jacket are utilized. As previouslystated, however, the form of my invention illustrated in FIG. 1 issufficient for the heating of a normal home; whereas the form of myinvention illustrated in FIG. 2 is beneficial where a somewhat greatercapacity is required. Preferably, the housing is located above theboiler 10 and in registry therewith, as illustrated in FIG. 2, sincesuch an arrangement takes advantage of the natural tendency of theheated flue gases to rise, whereupon the heated flue gases from boiler10 will naturally pass upwardly through chimney 62 to chamber 64 ofupper housing 64. It will also be noted that in the embodiment of myinvention illustrated in FIG. 2 the preferred size of the boiler 10 andupper housing 60 is greater than that of the boiler 10 shown in FIG. 1.More specifically, in the form of my invention shown in FIG. 2, both theunit 10 and the unit 60 have performed satisfactorily where the overalllength of each unit (from front cover to rear cover) is approximately 12feet 8 inches and where the outside diameter of each unit isapproximately 3 feet 9 inches. It will be understood, however, that thedimensions mentioned herein are in no way critical but merely are statedas being illustrative of the general size of working units embodying myinvention.

Although not expressly emphasized hereinbefore, the flue restrictorplates 48 and 78 from an important part of my invention, because theseplates restrict the reverse flow of the heated flue gases in such a waythat the flue gases are forced against the outer surface of waterjackets 30 and 72 in order to maximize heat transfer between the fluegases, during their reverse flow, and the respective water jackets. Itwill also be noted that the restrictor plates are maintained properlyspaced from the adjacent water jacket outer surface by means of studs86. Note also that a plate 88 may be provided between the front end ofwater jacket 30 and the inner surface of outer wall 12, as shown mostclearly in FIG. 1. This plate functions not only as a support for theinner end of the water jacket, but also acts as a baffle to help deflectthe flow of flue gases to stack 50.

While there is shown and described herein certain specific structureembodying the invention, it will be manifest to those skilled in the artthat various modifications and rearrangements of the parts may be madewithout departing from the spirit and scope of the underlying inventiveconcept and that the same is not limited to the particular forms hereinshown and described except insofar as indicated by the scope of theappended claims.

What is claimed is:

1. A hot boiler comprising a cylindrical housing defined by an outerinsulated cylindrical wall having a front cover closing off one endthereof and a rear cover closing off the other end, an inner combustionchamber located within said housing and extending axially andconcentrically thereof, said chamber extending from said front cover andterminating short of said rear cover, an annular water jacketsurrounding said chamber, a cylindrical restrictor plate extending fromsaid rear cover and terminating short of said front cover,

said restrictor plate being located between said water jacket and saidouter wall and being spaced from each, said restrictor plate and saidouter wall defining therebctween a dead-air insulation space an exhauststack extending through said outer wall and outwardly therefrom andlocated adjacent said front cover, inlet and outlet conduitscommunicating with said water jacket whereby water is continuouslycirculated therethrough. an opening in said front cover. and burnermeans located outside said front cover and firing through said opening,whereby the heated flue gases are forced rearwardly through saidcombustion chamber, and then forwardly between the outside of the waterjacket and the inside of the restrictor plate and then are exhausted outsaid stack.

2. In the boiler of claim 1, said inlet conduit making communicationwith said water jacket adjacent said front cover, and said outletconduit making communication with said water jacket adjacent said rearcover.

3. In the boiler of claim 2, said exhaust stack being located adjacentsaid front cover.

4. In the boiler of claim 3, a second cylindrical housing constructedsimilarly to said first housing and mounted adjacent thereto, saidoutlet conduit interconnecting the water jackets of said first andsecond housings, said exhaust stack communicating with the inner chamberof said second housing whereby the flue gases from said first housingpass through the inner chamber of said second housing and thenbackwardly between the water jacket and restrictor plate of said secondhousing, outlet means communicating with the water jacket of said secondhousing. and stack means communicating with said second housing toexhaust the flue gases therefrom.

5. in the boiler of claim 4, said outlet conduit communicating with thewater jacket of said second housing at a point adjacent the rear coverthereof, said outlet means communicating with the water jacket of saidsecond housing at a point adjacent the front cover thereof, and saidstack means being located adjacent the front cover of said secondhousing.

6. 1n the boiler of claim 5, said first and second housings beinghorizontally disposed, with said second housing being located above saidfirst housing in registry therewith

1. A hot boiler comprising a cylindrical housing defined by an outerinsulated cylindrical wall having a front cover closing off one endthereof and a rear cover closing off the other end, an inner combustionchamber located within said housing and extending axially andconcentrically thereof, said chamber extending from said front cover andterminating short of said rear cover, an annular water jacketsurrounding said chamber, a cylindrical restrictor plate extending fromsaid rear cover and terminating short of said front cover, saidrestrictor plate being located between said water jacket and said outerwall and being spaced from each, said restrictor plate and said outerwall defining therebetween a dead-air insulation space, an exhaust stackextending through said outer wall and outwardly therefrom and locatedadjacent said front cover, inlet and outlet conduits communicating withsaid water jacket whereby water is continuously circulated therethrough,an opening in said front cover, and burner means located outside saidfront cover and firing through said opening, whereby the heated fluegases are forced rearwardly through said combustion chamber, and thenforwardly between the outside of the water jacket and the inside of therestrictor plate and then are exhausted out said stack.
 2. In the boilerof claim 1, said inlet conduit making communication with said waterjacket adjacent said front cover, and said outlet conduit makingcommunication with said water jacket adjacent said rear cover.
 3. In theboiler of claim 2, said exhaust stack being located adjacent said frontcover.
 4. In the boiler of claim 3, a second cylindrical housingconstructed similarly to said first housing and mounted adjacentthereto, said outlet conduit interconnecting the water jackets of saidfirst and second housings, said exhaust stack communicating with tHeinner chamber of said second housing whereby the flue gases from saidfirst housing pass through the inner chamber of said second housing andthen backwardly between the water jacket and restrictor plate of saidsecond housing, outlet means communicating with the water jacket of saidsecond housing, and stack means communicating with said second housingto exhaust the flue gases therefrom.
 5. In the boiler of claim 4, saidoutlet conduit communicating with the water jacket of said secondhousing at a point adjacent the rear cover thereof, said outlet meanscommunicating with the water jacket of said second housing at a pointadjacent the front cover thereof, and said stack means being locatedadjacent the front cover of said second housing.
 6. In the boiler ofclaim 5, said first and second housings being horizontally disposed,with said second housing being located above said first housing inregistry therewith.